640223 has 2 divisors, whose sum is σ = 640224. Its totient is φ = 640222.

The previous prime is 640219. The next prime is 640229. The reversal of 640223 is 322046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 640223 - 2² = 640219 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320111 + 320112.

It is an arithmetic number, because the mean of its divisors is an integer number (320112).

2⁶⁴⁰²²³ is an apocalyptic number.

640223 is a deficient number, since it is larger than the sum of its proper divisors (1).

640223 is an equidigital number, since it uses as much as digits as its factorization.

640223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 640223 is about 800.1393628612. The cubic root of 640223 is about 86.1873955835.

Adding to 640223 its reverse (322046), we get a palindrome (962269).

The spelling of 640223 in words is "six hundred forty thousand, two hundred twenty-three".